|
Journal of Applied Sciences and Environmental Management
World Bank assisted National Agricultural Research Project (NARP) - University of Port Harcourt
ISSN: 1119-8362
Vol. 21, No. 6, 2017, pp. 1067-1071
|
Bioline Code: ja17127
Full paper language: English
Document type: Research Article
Document available free of charge
|
|
Journal of Applied Sciences and Environmental Management, Vol. 21, No. 6, 2017, pp. 1067-1071
en |
Inhibitory Effect of African Pumpkin ( Momordica balsamina Linn.) Leaf Extract on Copper Corrosion in Acidic Media
MAIBULANGU, BM; 2 IBRAHIM, MB & AKINOLA, LK
Abstract
Inhibition of copper corrosion in acidic medium by ethanolic extract of Momordica balsamina
leaves was investigated. Findings reveal that the rate of copper corrosion increases with increasing temperature of the
medium but decreases as the concentration of the Momordica balsamina extract added to the medium increases.
Examination of the surface morphology of copper using Scanning Electron Microscopy (SEM) also reveals that while
the surface of copper was seriously damaged in acidic solution in the absence of Momordica balsamina extract,
addition of 0.8 mgL-1 of the extract significantly protected the copper surface from corrosion. Results obtained from
adsorption and thermodynamic studies reveal that the adsorption of the inhibitor on the surface of the copper metal
fitted well to both Freundlich (R2 ≥ 0.948) and Temkin (R2 ≥ 0.940) adsorption models and the low values of
activation energies obtained (Ea≤ 34.02 kJmol-1) indicate that the adsorption of the inhibitor on the copper surface
favors the mechanism of physical adsorption. Negative signs of ∆Gads obtained in the study suggest that the
adsorption of Momordica balsamina on the copper metal is thermodynamically favorable. The data obtained in this
study demonstrate that extract of Momordica balsamina leaves probably contains one or more chemical species that
protect copper against corrosion through the mechanism of physical adsorption.
Keywords
Adsorption; Copper; Corrosion; Inhibitor; Momordica balsamina
|
|
© Copyright 2017 - Journal of Applied Sciences and Environmental Management
|
|